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Abstract:

A method includes providing a patch including: a flexible base layer that
is mountable on and substantially conformable to a patient's body
surface, the base layer having opposed upper and lower primary surfaces;
a flexible substrate that is releasably attached to the upper primary
surface of the base layer and substantially conformable to the patient's
body surface; and at least one MRI-visible fiducial element defined by or
secured to the flexible substrate. The method further includes: securing
the base layer to the body surface to mount the patch on the body surface
such that the flexible substrate conforms to the body surface; MRI
scanning the patient with the patch on the body surface to generate
corresponding image data; identifying a physical location on the body
surface using the image data; and removing the flexible substrate from
the base layer.

Claims:

1. A method for identifying a physical location on a body surface of a
patient, the method comprising: providing a patch including: a flexible
base layer that is mountable on and substantially conformable to a
patient's body surface, the base layer having opposed upper and lower
primary surfaces; a flexible substrate that is releasably attached to the
upper primary surface of the base layer and substantially conformable to
the patient's body surface; and at least one MRI-visible fiducial element
defined by or secured to the flexible substrate; securing the base layer
to the body surface to mount the patch on the body surface such that the
flexible substrate conforms to the body surface; thereafter MRI scanning
the patient with the patch on the body surface to generate corresponding
image data; thereafter identifying a physical location on the body
surface using the image data; and removing at least a portion of the
flexible substrate from the base layer.

2. The method of claim 1 wherein the patch includes a layer of adhesive
disposed on a lower surface of the flexible substrate and engaging the
upper primary surface of the base layer and releasably attaching the
flexible substrate to the base layer.

3. The method of claim 1 wherein the patch includes an adhesive disposed
on the lower primary surface of the base layer, and the method includes
attaching the base layer to the body surface using the adhesive.

4. The method of claim 3 wherein the patch includes a release liner
releasably backing the adhesive on the lower primary surface of the base
layer, and the method includes removing the release liner to expose the
adhesive prior to the securing step.

5. The method of claim 1 wherein the patch includes indicia on the base
layer corresponding to the at least one MRI-visible fiducial element on
the flexible substrate.

6. The method of claim 5 wherein the patch includes second indicia on the
flexible substrate corresponding to the indicia on the base layer.

7. The method of claim 1 wherein the at least one MRI-visible fiducial
element includes a plurality of MRI-visible fiducial elements defined by
or secured to the flexible substrate.

8. The method of claim 7 wherein the MRI-visible fiducial elements are
arranged in a defined pattern.

9. The method of claim 8 wherein the patch includes indicia on the base
layer corresponding to the MRI-visible fiducial elements on the flexible
substrate, wherein the indicia has a second prescribed pattern having a
higher resolution than the defined pattern of the MRI-visible fiducial
elements on the flexible substrate.

10. The method of claim 8 wherein the defined pattern includes a grid
pattern defining a coordinate system.

11. The method of claim 10 including codified indicia representing the
coordinate system.

12. The method of claim 7 wherein at least one of the MRI-visible
fiducial elements has a first MRI-visible geometric shape, and at least
one of the MRI-visible fiducial elements has a second MRI-visible
geometric shape different from the first MRI-visible geometric shape.

13. The method of claim 7 wherein at least some of the MRI-visible
fiducial elements include a pocket containing MRI-visible material.

14. The method of claim 13 wherein the MRI-visible material includes an
MRI-visible liquid.

15. The method of claim 7 wherein at least some of the MRI-visible
fiducial elements are selectively discretely removable from the flexible
substrate, and the method includes removing at least one of the
MRI-visible fiducial elements from the flexible substrate after MRI
scanning the patient with the patch on the body surface.

16. The method of claim 1 wherein the flexible substrate includes a pull
tab to facilitate removal of the flexible substrate from the base layer.

17. The method of claim 1 wherein the base layer is frangible, and the
method includes tearing the base layer to permit selective access to the
body surface when the base layer is mounted thereon and the flexible
substrate has been at least partially removed.

18. The method of claim 1 wherein: MRI scanning the patient with the
patch on the body surface includes MRI scanning an MRI-visible reference
indicator on the patch to generate corresponding reference image data;
and the method further includes programmatically determining an
orientation of the patch using the reference image data.

19. The method of claim 1 wherein the patch includes perforations defined
in the flexible substrate to thereby enhance conformity of the flexible
substrate to the body surface.

20. The method of claim 1 wherein the flexible substrate is formed of a
stretchable material to allow the flexible substrate to conform to a head
body surface.

21. The method of claim 1 wherein the flexible substrate is a mesh.

22. The method of claim 1 wherein the patch includes a supply of ink and
the method includes transferring at least some of the ink from the patch
to the patient's body surface when the patch is mounted on the patient's
body surface.

23. The method of claim 1 wherein at least one of the MRI-visible
fiducial elements has a width and a height greater than its width to
define a heightwise axis.

24. The method of claim 1 wherein the flexible substrate has a thickness
in the range of from about 0.001 to 0.100 inches.

25. The method of claim 1 wherein the flexible substrate is a substrate
material selected from the group consisting of polyvinyl, PET, silicone,
polyethylene, polyurethane, and polyamide.

26. The method of claim 1 further including: generating an image of the
patient in a logical space; determining in the logical space a desired
entry location on the body surface for insertion of instrumentation into
the patient; and programmatically determining a physical location on the
patch corresponding to the desired entry location.

27. The method of claim 26 wherein: determining in the logical space the
desired entry location includes determining a desired trajectory line;
and determining the physical location on the patch corresponding to the
desired entry location includes determining a location of intersection
between the desired trajectory line and the patch.

28. The method of claim 26 wherein the body surface is on a head of the
patient and the method further includes forming a burr hole in the
patient's skull proximate the physical location.

29. The method of claim 1 wherein the flexible substrate includes a
flexible sheet and the at least one MRI-visible fidicial element is
releasably secured to the flexible sheet.

30. The method of claim 29 wherein the patch includes a layer of adhesive
disposed on a lower surface of the flexible sheet and engaging the upper
primary surface of the base layer and releasably attaching the flexible
sheet to the base layer.

31. The method of claim 29 wherein the flexible sheet is peelably
releasably attached to the base layer, and the step of removing at least
a portion of the flexible substrate from the base layer includes peeling
the flexible sheet off of the base layer with the at least one
MRI-visible fiducial element disposed on the flexible sheet.

Description:

RELATED APPLICATION(S)

[0001] This application is a divisional of and claims priority from U.S.
patent application Ser. No. 12/236,621, filed Sep. 24, 2008, which claims
the benefit of and priority to U.S. Provisional Patent Application No.
60/974,821, filed Sep. 24, 2007, the disclosures of which are
incorporated herein by reference as if set forth in their entireties.

FIELD OF THE INVENTION

[0002] The present invention relates generally to medical systems and
methods and, more particularly, to in vivo medical systems and methods.

BACKGROUND OF THE INVENTION

[0003] Deep Brain Stimulation (DBS) is becoming an acceptable therapeutic
modality in neurosurgical treatment of patients suffering from chronic
pain, Parkinson's disease or seizure, and other medical conditions. Other
electro-stimulation therapies have also been carried out or proposed
using internal stimulation of the sympathetic nerve chain and/or spinal
cord, etc.

[0004] One example of a prior art DBS system is the Activa® system
from Medtronic, Inc. The Activa® system includes an implantable pulse
generator stimulator that is positioned in the chest cavity of the
patient and a lead with axially spaced apart electrodes that is implanted
with the electrodes disposed in neural tissue. The lead is tunneled
subsurface from the brain to the chest cavity connecting the electrodes
with the pulse generator. These leads can have multiple exposed
electrodes at the distal end that are connected to conductors which run
along the length of the lead and connect to the pulse generator placed in
the chest cavity.

[0005] It is believed that the clinical outcome of certain medical
procedures, particularly those using DBS, may depend on the precise
location of the electrodes that are in contact with the tissue of
interest. For example, to treat Parkinson's tremor, presently the DBS
probes are placed in neural tissue with the electrodes transmitting a
signal to the thalamus region of the brain. DBS stimulation leads are
conventionally implanted during a stereotactic surgery, based on
pre-operative MRI and CT images. These procedures can be long in duration
and may have reduced efficacy as it has been reported that, in about 30%
of the patients implanted with these devices, the clinical efficacy of
the device/procedure is less than optimum. Notwithstanding the above,
there remains a need for alternative MRI-guided interventional tools for
DBS, as well as for other interventional medical procedures.

SUMMARY OF THE INVENTION

[0006] According to embodiments of the present invention, an
MRI-compatible patch for identifying a location includes a flexible base
layer, a flexible substrate and at least one MRI-visible fiducial
element. The flexible base layer is mountable on and substantially
conformable to a patient's body surface. The base layer has opposed upper
and lower primary surfaces. The flexible substrate is releasably attached
to the upper primary surface of the base layer and substantially
conformable to the patient's body surface. The at least one MRI-visible
fiducial element is defined by or secured to the flexible substrate. The
MRI-visible fiducial elements are arranged in a defined pattern.

[0007] According to some embodiments, the patch includes an adhesive to
releasably attach the flexible substrate to the base layer.

[0008] The patch may include an adhesive disposed on the lower primary
surface of the base layer to attach the base layer to the body surface.

[0009] The patch may include indicia on the base layer corresponding to
the MRI-visible fiducial elements on the flexible substrate. The patch
may include second indicia on the flexible substrate corresponding to the
indicia on the base layer.

[0010] In some embodiments, the patch includes a plurality of the
MRI-visible fiducial elements. The fiducial elements may be arranged in a
defined pattern. Indicia may be provided on the base layer corresponding
to the MRI-visible fiducial elements on the flexible substrate, wherein
the indicia has a second prescribed pattern having a higher resolution
than the defined pattern of the MRI-visible fiducial elements on the
flexible substrate. In some embodiments, the defined pattern includes a
grid pattern defining a coordinate system. The patch may include codified
indicia representing the coordinate system.

[0011] The flexible substrate can include a pull tab to facilitate removal
of the flexible substrate from the base layer.

[0012] In some embodiments, the base layer is frangible to permit
selective access to the body surface when the base layer is mounted
thereon and the flexible substrate has been at least partially removed.

[0013] According to some embodiments, the patch includes at least one
MRI-visible reference indicator to indicate an orientation of the patch.

[0014] In some embodiments, at least one of the MRI-visible fiducial
elements has a first MRI-visible geometric shape, and at least one of the
MRI-visible fiducial elements has a second MRI-visible geometric shape
different from the first MRI-visible geometric shape.

[0015] According to some embodiments, at least some of the MRI-visible
fiducial elements include a pocket containing MRI-visible material. The
MRI-visible material may include an MRI-visible liquid.

[0016] At least some of the MRI-visible fiducial elements may be
selectively discretely removable from the flexible substrate to permit
access to the body surface.

[0017] According to some embodiments, the patch includes perforations
defined in the flexible substrate to thereby enhance conformity of the
flexible substrate to the body surface.

[0018] The flexible substrate can be formed of a stretchable material to
allow the flexible substrate to conform to a head body surface.

[0019] According to some embodiments, the flexible substrate has a
thickness in the range of from about 0.001 to 0.100 inches.

[0020] According to some embodiments, the flexible substrate is a
substrate material selected from the group consisting of polyvinyl, PET,
silicone, polyethylene, polyurethane, and polyamide.

[0021] According to some embodiments, the patch further includes: a
plurality of MRI-visible fiducial elements defined by or secured to the
flexible substrate, wherein the fiducial elements are arranged in a
defined pattern; an adhesive disposed on the lower primary surface of the
base layer to attach the base layer to the body surface; a release liner
backing and releasably secured to the adhesive; and indicia on the base
layer corresponding to the MRI-visible fiducial elements on the flexible
substrate; and at least one MRI-visible reference indicator to indicate
an orientation of the patch; wherein at least some of the MRI-visible
fiducial elements include a pocket containing MRI-visible liquid, and
wherein the defined pattern includes a grid pattern defining a coordinate
system.

[0022] According to embodiments of the present invention, a method for
identifying a physical location on a body surface of a patient includes
providing a patch including: a flexible base layer that is mountable on
and substantially conformable to a patient's body surface, the base layer
having opposed upper and lower primary surfaces; a flexible substrate
that is releasably attached to the upper primary surface of the base
layer and substantially conformable to the patient's body surface; and at
least one MRI-visible fiducial element defined by or secured to the
flexible substrate. The method further includes: securing the base layer
to the body surface to mount the patch on the body surface such that the
flexible substrate conforms to the body surface; MRI scanning the patient
with the patch on the body surface to generate corresponding image data;
identifying a physical location on the body surface using the image data;
and removing the flexible substrate from the base layer.

[0023] According to some embodiments, the patch includes a plurality of
the MRI-visible fiducial elements. In some embodiments, the fiducial
elements are arranged in a defined pattern.

[0024] According to embodiments of the present invention, a method for
identifying a physical location on a body surface of a patient residing
in physical space includes providing a patch residing in physical space
and including: a flexible substrate that is mountable on and
substantially conformable to the body surface; and at least one
MRI-visible fiducial element defined by or secured to the flexible
substrate. The method further includes: mounting the patch on the body
surface such that the flexible substrate conforms to the body surface;
MRI scanning the patient with the patch on the body surface to generate
corresponding image data; and identifying a physical location on the body
surface using the image data, including: generating an image of the
patient in a logical space; determining in the logical space a desired
entry location on the body surface for insertion of instrumentation into
the patient; and programmatically determining a physical location on the
patch corresponding to the desired entry location.

[0025] In some embodiments, determining in the logical space the desired
entry location includes determining a desired trajectory line, and
determining the physical location on the patch corresponding to the
desired entry location includes determining a location of intersection
between the desired trajectory line and the patch. The method may include
programmatically determining in the logical space the desired entry
location and the desired trajectory line. The method can include
displaying the desired entry location and the desired trajectory line on
a display device to an operator.

[0026] According to some embodiments, the patch includes a plurality of
the MRI-visible fiducial elements. In some embodiments, the fiducial
elements are arranged in a defined pattern. According to some
embodiments, the method includes displaying the image of the patient and
a graphical overlay on a display to an operator. The graphical overlay
indicates at least a portion of the defined pattern of the MRI-visible
fiducial elements.

[0027] The method may further include marking the body surface at a
location corresponding to the physical location on the patch.

[0028] According to some embodiments, the body surface is on the patient's
head and the method includes forming a burr hole in the patient's skull
proximate the physical location.

[0029] The mounting step may comprise releasably attaching the flexible
substrate to the body surface prior to the step of MRI scanning the
patient with the patch on the body surface. According to some
embodiments, the patch includes a flexible base layer having opposed
upper and lower primary surfaces, wherein the flexible substrate is
releasably attached to the upper primary surface of the base layer, and
the method includes: securing the base layer to the body surface prior to
the step of MRI scanning the patient with the patch on the body surface;
and removing the flexible substrate from the base layer after the step of
MRI scanning the patient with the patch on the body surface.

[0030] The method may include removing at least one of the fiducial
elements from the flexible substrate after the step of MRI scanning the
patient with the patch on the body surface to permit access to the body
surface.

[0031] In some embodiments, at least some of the MRI-visible fiducial
elements include a pocket containing MRI-visible material.

[0032] In some embodiments, the method includes: mounting a plurality of
the patches on the body surface in close proximity to one another; and
thereafter MRI scanning the patient with the plurality of patches on the
body surface to generate corresponding image data.

[0033] According to some embodiments, MRI scanning the patient with the
patch on the body surface includes MRI scanning an MRI-visible reference
indicator on the patch to generate corresponding reference image data.
The method further includes programmatically determining an orientation
of the patch using the reference image data.

[0034] According to embodiments of the present invention, a computer
program product for identifying a physical location on a body surface of
a patient using a patch mounted on the body surface and including at
least one MRI-visible fiducial element includes a computer readable
medium having computer usable program code embodied therein, the computer
readable program code comprising: computer readable program code
configured to generate an image of the patient and the patch in a logical
space, the image corresponding to an MRI scan of the patient with the
patch on the body surface; computer readable program code configured to
determine in the logical space a desired trajectory line for insertion of
instrumentation into the patient; and computer usable program code
configured to programmatically determine a location of intersection
between the desired trajectory line and the patch.

[0035] According to embodiments of the present invention, a system for
designating a physical location on a body surface of a patient includes a
patch and a controller. The patch includes: a flexible substrate that is
mountable on and conformable to the body surface; and at least one
MRI-visible fiducial element defined by or secured to the flexible
substrate. The controller is adapted to communicate with an MRI scanner
that is operable to scan the patient with the patch on the body surface
and to generate corresponding image data. The controller processes the
image data from the MRI scanner to programmatically identify a physical
location on the body surface.

[0036] In some embodiments, the controller is operable to display
correlated representations of the at least fiducial element and the
patient.

[0037] According to embodiments of the present invention, a medical
(surgical) kit for designating a physical location on a head of a patient
includes a patch and a head marking tool. The patch includes a flexible
base layer, a flexible substrate and at least one MRI-visible fiducial
element. The flexible base layer is mountable on and substantially
conformable to a patient's body surface. The base layer has opposed upper
and lower primary surfaces. The flexible substrate is releasably attached
to the upper primary surface of the base layer and substantially
conformable to the patient's body surface. The MRI-visible fiducial
element is defined by or secured to the flexible substrate. The head
marking tool is configured to mark the head of the patient.

[0038] In some embodiments, the head marking tool is configured to mark a
skull of the patent.

[0039] According to embodiments of the present invention, an
MRI-compatible patch for identifying a location includes a flexible
substrate that is mountable on and substantially conformable to a
patient's body surface. A plurality of MRI-visible fiducial elements are
defined by or secured to the flexible substrate. The MRI-visible fiducial
elements are arranged in a defined pattern. The plurality of MRI-visible
fiducial elements include at least one MRI-visible reference indicator to
indicate an orientation of the patch.

[0040] According to embodiments of the present invention, a method for
identifying a physical location on a body surface of a patient residing
in physical space includes providing a patch residing in physical space
and including: a flexible substrate that is mountable on and
substantially conformable to the body surface; and at least one
MRI-visible fiducial element defined by or secured to the flexible
substrate. The method further includes: mounting the patch on the body
surface such that the flexible substrate conforms to the body surface;
MRI scanning the patient with the patch on the body surface to generate
corresponding image data; generating an image of the patient in a logical
space; and programmatically determining an orientation of the patch in
the logical space using the image data.

[0041] In some embodiments, the patch includes an MRI-visible reference
indicator and programmatically determining the orientation of the patch
in the logical space using the image data includes programmatically
determining the orientation of the patch in the logical space using image
data corresponding to the MRI-visible reference indicator.

[0042] Further features, advantages and details of the present invention
will be appreciated by those of ordinary skill in the art from a reading
of the figures and the detailed description of the preferred embodiments
that follow, such description being merely illustrative of the present
invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIGS. 1 and 2 are flowcharts representing methods according to
embodiments of the present invention.

[0044]FIG. 3 is a top perspective view of an exemplary patch assembly
according to embodiments of the present invention.

[0045]FIG. 4 is an enlarged, fragmentary, cross-sectional view of the
patch assembly of FIG. 3 taken along the line 4-4 of FIG. 3.

[0046] FIG. 5 is an exploded, top perspective view of the patch assembly
of FIG. 3.

[0048] FIG. 16 is a top perspective view of a patch assembly according to
further embodiments of the present invention.

[0049] FIG. 17 is a top plan view of a patch according to further
embodiments of the present invention.

[0050] FIG. 18 is a top plan view of a patch according to further
embodiments of the present invention.

[0051] FIG. 19 is a top plan view of a patch according to further
embodiments of the present invention.

[0052] FIG. 20 is a top plan view of a base layer according to further
embodiments of the present invention, wherein a portion of the base layer
is partially removed.

[0053] FIG. 21 is a top perspective view of a patch according to further
embodiments of the present invention, wherein a tab or component thereof
is partially removed.

[0054] FIG. 22 is a top perspective view of the patch of FIG. 21, wherein
a group of tabs thereof is partially removed.

[0055]FIG. 23 is a plan view of a patch according to further embodiments
of the present invention.

[0056] FIG. 24 is a plan view of a patch according to further embodiments
of the present invention mounted on a patient's head.

[0057] FIG. 25 is a fragmentary, perspective view of a top layer including
MRI-visible tabs according to further embodiments of the present
invention.

[0058]FIG. 26 is a fragmentary, plan view of a base layer according to
further embodiments of the present invention mounted on a patient's head
and wherein a portion of the base layer is partially removed.

[0059]FIG. 27 is a plan view of a patch system according to embodiments
of the present invention mounted on a patient.

[0060]FIG. 28 is a data processing system according to embodiments of the
present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0061] The present invention now is described more fully hereinafter with
reference to the accompanying drawings, in which some embodiments of the
invention are shown. This invention may, however, be embodied in many
different forms and should not be construed as limited to the embodiments
set forth herein; rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the scope
of the invention to those skilled in the art.

[0062] Like numbers refer to like elements throughout. In the figures, the
thickness of certain lines, layers, components, elements or features may
be exaggerated for clarity.

[0063] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of the
invention. As used herein, the singular forms "a", "an" and "the" are
intended to include the plural forms as well, unless the context clearly
indicates otherwise. It will be further understood that the terms
"comprises" and/or "comprising," when used in this specification, specify
the presence of stated features, steps, operations, elements, and/or
components, but do not preclude the presence or addition of one or more
other features, steps, operations, elements, components, and/or groups
thereof. As used herein, the term "and/or" includes any and all
combinations of one or more of the associated listed items.

[0064] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this invention
belongs. It will be further understood that terms, such as those defined
in commonly used dictionaries, should be interpreted as having a meaning
that is consistent with their meaning in the context of the specification
and relevant art and should not be interpreted in an idealized or overly
formal sense unless expressly so defined herein. Well-known functions or
constructions may not be described in detail for brevity and/or clarity.

[0065] It will be understood that when an element is referred to as being
"on", "attached" to, "connected" to, "coupled" with, "contacting", etc.,
another element, it can be directly on, attached to, connected to,
coupled with or contacting the other element or intervening elements may
also be present. In contrast, when an element is referred to as being,
for example, "directly on", "directly attached" to, "directly connected"
to, "directly coupled" with or "directly contacting" another element,
there are no intervening elements present. It will also be appreciated by
those of skill in the art that references to a structure or feature that
is disposed "adjacent" another feature may have portions that overlap or
underlie the adjacent feature.

[0066] Spatially relative terms, such as "under", "below", "lower",
"over", "upper" and the like, may be used herein for ease of description
to describe one element or feature's relationship to another element(s)
or feature(s) as illustrated in the figures. It will be understood that
the spatially relative terms are intended to encompass different
orientations of the device in use or operation in addition to the
orientation depicted in the figures. For example, if the device in the
figures is inverted, elements described as "under" or "beneath" other
elements or features would then be oriented "over" the other elements or
features. Thus, the exemplary term "under" can encompass both an
orientation of "over" and "under". The device may be otherwise oriented
(rotated 90 degrees or at other orientations) and the spatially relative
descriptors used herein interpreted accordingly. Similarly, the terms
"upwardly", "downwardly", "vertical", "horizontal" and the like are used
herein for the purpose of explanation only unless specifically indicated
otherwise.

[0067] Exemplary embodiments are described below with reference to block
diagrams and/or flowchart illustrations of methods, apparatus (systems
and/or devices) and/or computer program products. It is understood that a
block of the block diagrams and/or flowchart illustrations, and
combinations of blocks in the block diagrams and/or flowchart
illustrations, can be implemented by computer program instructions. These
computer program instructions may be provided to a processor of a general
purpose computer, special purpose computer, and/or other programmable
data processing apparatus to produce a machine, such that the
instructions, which execute via the processor of the computer and/or
other programmable data processing apparatus, create means
(functionality) and/or structure for implementing the functions/acts
specified in the block diagrams and/or flowchart block or blocks.

[0068] These computer program instructions may also be stored in a
computer-readable memory that can direct a computer or other programmable
data processing apparatus to function in a particular manner, such that
the instructions stored in the computer-readable memory produce an
article of manufacture including instructions which implement the
functions/acts specified in the block diagrams and/or flowchart block or
blocks.

[0069] The computer program instructions may also be loaded onto a
computer or other programmable data processing apparatus to cause a
series of operational steps to be performed on the computer or other
programmable apparatus to produce a computer-implemented process such
that the instructions which execute on the computer or other programmable
apparatus provide steps for implementing the functions/acts specified in
the block diagrams and/or flowchart block or blocks.

[0070] Accordingly, exemplary embodiments may be implemented in hardware
and/or in software (including firmware, resident software, micro-code,
etc.). Furthermore, exemplary embodiments may take the form of a computer
program product on a computer-usable or computer-readable storage medium
having computer-usable or computer-readable program code embodied in the
medium for use by or in connection with an instruction execution system.
In the context of this document, a computer-usable or computer-readable
medium may be any medium that can contain, store, communicate, propagate,
or transport the program for use by or in connection with the instruction
execution system, apparatus, or device.

[0071] The computer-usable or computer-readable medium may be, for example
but not limited to, an electronic, magnetic, optical, electromagnetic,
infrared, or semiconductor system, apparatus, device, or propagation
medium. More specific examples (a non-exhaustive list) of the
computer-readable medium would include the following: an electrical
connection having one or more wires, a portable computer diskette, a
random access memory (RAM), a read-only memory (ROM), an erasable
programmable read-only memory (EPROM or Flash memory), an optical fiber,
and a portable compact disc read-only memory (CD-ROM). Note that the
computer-usable or computer-readable medium could even be paper or
another suitable medium upon which the program is printed, as the program
can be electronically captured, via, for instance, optical scanning of
the paper or other medium, then compiled, interpreted, or otherwise
processed in a suitable manner, if necessary, and then stored in a
computer memory.

[0072] Computer program code for carrying out operations of data
processing systems discussed herein may be written in a high-level
programming language, such as Java, AJAX (Asynchronous JavaScript), C,
and/or C++, for development convenience. In addition, computer program
code for carrying out operations of exemplary embodiments may also be
written in other programming languages, such as, but not limited to,
interpreted languages. Some modules or routines may be written in
assembly language or even micro-code to enhance performance and/or memory
usage. However, embodiments are not limited to a particular programming
language. It will be further appreciated that the functionality of any or
all of the program modules may also be implemented using discrete
hardware components, one or more application specific integrated circuits
(ASICs), or a programmed digital signal processor or microcontroller.

[0073] The flowcharts and block diagrams of certain of the figures herein
illustrate exemplary architecture, functionality, and operation of
possible implementations of embodiments of the present invention. In this
regard, each block in the flow charts or block diagrams represents a
module, segment, or portion of code, which comprises one or more
executable instructions for implementing the specified logical
function(s). It should also be noted that in some alternative
implementations, the functions noted in the blocks may occur out of the
order noted in the figures. For example, two blocks shown in succession
may in fact be executed substantially.

[0074] The term "MRI-visible" means that a device or feature thereof is
visible, directly or indirectly, in an MRI image. The visibility may be
indicated by the increased SNR of the MRI signal proximate to the device
(the device can act as an MRI receive antenna to collect signal from
local tissue) and/or that the device actually generates MRI signal
itself, such as via suitable hydro-based coatings and/or fluid (typically
aqueous solutions) filled cavities.

[0075] The term "MRI-compatible" means that a device is safe for use in an
MRI environment and/or can operate as intended in an MRI environment,
and, as such, if residing within the high-field strength region of the
magnetic field, is typically made of a non-ferromagnetic MRI-compatible
material(s) suitable to reside and/or operate in a high magnetic field
environment.

[0076] The term "programmatically" refers to operations directed and/or
primarily carried out electronically by computer program modules, code
and instructions.

[0077] The term "fiducial marker" refers to a marker that can be
identified visually and/or using electronic image recognition, electronic
interrogation of MRI image data, or three-dimensional electrical signals
to define a position and/or find the feature or component in 3-D space.

[0078] Patches in accordance with embodiments of the present invention can
be configured to identify or designate a location on a body. The location
may be identified in order to determine a desired position, orientation
or operation of a guide apparatus. The guide apparatus may be used to
guide and/or place diagnostic or interventional devices and/or therapies
to any desired internal region of the body or object using MRI and/or in
an MRI scanner or MRI interventional suite. The object can be any object,
and may be particularly suitable for animal and/or human subjects. In
some embodiments, the guide apparatus is used to place implantable DBS
leads for brain stimulation, typically deep brain stimulation. In some
embodiments, the guide apparatus can be configured to deliver tools or
therapies that stimulate a desired region of the sympathetic nerve chain.
Other uses inside or outside the brain include stem cell placement, gene
therapy or drug delivery for treating physiological conditions. Some
embodiments can be used to treat tumors. Some embodiments can be used for
RF ablation, laser ablation, cryogenic ablation, etc. In some
embodiments, the interventional tools can be configured to facilitate
high resolution imaging via intrabody imaging coils (receive antennas),
and/or the interventional tools can be configured to stimulate local
tissue, which can facilitate confirmation of proper location by
generating a physiologic feedback (observed physical reaction or via
fMRI).

[0079] In some embodiments, the patch is used to identify a location on
the body for delivering bions, stem cells or other target cells to
site-specific regions in the body, such as neurological target and the
like. In some embodiments, the patch is used to identify a location on
the body for introducing stem cells and/or other cardio-rebuilding cells
or products into cardiac tissue, such as a heart wall via a minimally
invasive MRI-guided procedure, while the heart is beating (i.e., not
requiring a non-beating heart with the patient on a heart-lung machine).
Examples of known stimulation treatments and/or target body regions are
described in U.S. Pat. Nos. 6,708,064; 6,438,423; 6,356,786; 6,526,318;
6,405,079; 6,167,311; 6539,263; 6,609,030 and 6,050,992, the contents of
which are hereby incorporated by reference as if recited in full herein.

[0080] Generally stated, some embodiments of the invention are directed to
MRI interventional procedures including locally placing interventional
tools or therapies in vivo to site-specific regions using an MRI system.
The interventional tools can be used to define an MRI-guided trajectory
or access path to an in vivo treatment site.

[0081] In some embodiments, MRI can be used to visualize (and/or locate) a
therapeutic region of interest inside the brain or other body locations,
to visualize an MRI-visible patch according to embodiments of the present
invention, and to visualize (and/or locate) an interventional tool or
tools that will be used to deliver therapy and/or to place a chronically
implanted device that will deliver one ore more therapies. Then, using
the three-dimensional data produced by the MRI system regarding the
location of the therapeutic region of interest and the location of the
interventional tool, the system and/or physician can make positional
adjustments to the interventional tool so as to align the trajectory of
the interventional tool, so that when inserted into the body, the
interventional tool will intersect with the therapeutic region of
interest. With the interventional tool now aligned with the therapeutic
region of interest, an interventional probe can be advanced, such as
through an open lumen inside of the interventional tool, so that the
interventional probe follows the trajectory of the interventional tool
and proceeds to the therapeutic region of interest.

[0082] According to some methods of the present invention and with
reference to FIG. 1, a method is provided for identifying a physical
location on a body surface (e.g., the scalp) of a patient. A patch is
provided including a flexible base layer that is mountable on and
substantially conformable to the body surface and has opposed upper and
lower primary surfaces, a flexible substrate that is releasably attached
to the upper primary surface of the base layer and substantially
conformable to the body surface, and a plurality of MRI-visible fiducial
elements defined by or secured to the flexible substrate (Block 60). The
MRI-visible fiducial elements are arranged in a defined pattern. The
patch is mounted on the body surface such that the flexible substrate
conforms to the body surface (Block 62). The patient is MRI scanned with
the patch on the body surface to generate corresponding image data (Block
64). A physical location on the body surface is identified using the
image data (Block 66). The flexible substrate is removed from the base
layer (Block 68). Some embodiments of the present invention include a
computer program product comprising computer usable program code embodied
in a computer usable medium and configured to programmatically execute
the step of identifying the physical location on the body surface using
the image data.

[0083] According to some embodiments of the present invention and with
reference to FIG. 2, a method is provided for identifying a physical
location on a body surface of a patient using a patch mounted on the body
surface. The patch includes a plurality of MRI-visible fiducial elements
arranged in a defined pattern. An image of the patient and the patch in a
logical space is generated (Block 70). The image corresponds to an MRI
scan of the patient with the patch on the body surface. A desired
trajectory line for insertion of instrumentation into the patient is
determined in the logical space (Block 72). A location of intersection
between the desired trajectory line and the patch is programmatically
determined (Block 74). In some embodiments, the location of intersection
is visually displayed. Some embodiments of the present invention include
a computer program product comprising computer usable program code
embodied in a computer usable medium and configured to programmatically
determine the location of intersection between the desired trajectory
line and the patch.

[0084] With reference to FIGS. 1-5, an integral patch assembly 101
according to embodiments of the present invention is shown therein. The
patch assembly 101 includes a patch 100 and a release liner 102. The
patch 100 includes a base substrate or layer 110, a primary or base
adhesive 120, an MRI-visible or top substrate or layer 130, and a
secondary or top adhesive 122.

[0085] With reference to FIGS. 4 and 5, the base layer 110 has opposed
upper and lower primary surfaces 112A, 112B. The base adhesive 120 coats
the lower primary surface 112B. The release liner 102 is releasably
adhered to the base layer 110 by the base adhesive 120, which remains
with the base layer 110 when the release liner 102 is removed. The
release line 102 may include a pull tab 102A. Optionally, the base layer
110 may include a pull tab 114 free of the adhesive 120.

[0086] The base layer 110 is formed of a flexible material. According to
some embodiments, the base layer 110 is formed of a biocompatible
polymeric material suitable for surgical use in MRI systems. Suitable
polymeric materials may include polyvinyl, PET, silicone, polyethylene,
polyurethane, and/or polyamide.

[0087] According to some embodiments, the base layer 110 has a thickness
in the range of from about 0.001 to 0.100 inches. According to some
embodiments, the base layer 110 has a total area in the range of from
about 1 to 900 cm2.

[0088] According to some embodiments, the base adhesive 120 is a
biocompatible adhesive that has adhesive properties that ensure a secure,
but releasable, bond with human skin and/or an incise drape.

[0089] With reference to FIGS. 3 and 4, the top layer 130 has an integral,
bi-layer construction including an inner layer 134 and an outer layer
136. However, other constructions in accordance with aspects of the
invention are contemplated, as well. The top layer 130 has a lower
surface that is coated with the top adhesive 122. The top layer 130
includes a pull tab 138 extending beyond an edge thereof. A portion or
all of the pull tab 138 may be free of the adhesive 122.

[0090] The outer layer 136 is attached to the inner layer 134 at seams 144
(FIG. 4) to form a plurality of discrete pockets or cavities 142 (FIG. 4)
between the seams 144 and the layers 134, 136. The layers 134, 136 may be
attached via any suitable means such as bonded by adhesive, heat bonding
or any other suitable technique. Each pocket 142 is filled with a mass
146 (FIG. 4) of an MRI-visible material 146 to form a respective
MRI-visible fiducial element, bubble or tab 140. The plurality of tabs
140 can be arranged in a predefined array 168 and include a reference tab
140R (FIG. 3) positioned or shaped to be readily discerned with respect
to the other tabs. While MRI-visible tabs 140, 140R are illustrated and
described, other types and construction of MRI-visible fiducial elements
may be employed in accordance with further embodiments. For example, the
reference tab 140R may be replaced or supplemented with an MRI-visible
coating.

[0091] The layers 134, 136 are formed of a flexible material. According to
some embodiments, the layers 134, 136 are formed of a polymeric material.
Suitable polymeric materials may include polyvinyl, PET, silicone,
polyethylene, polyurethane, and/or polyamide.

[0092] The MRI-visible material 146 may be any suitable material.
According to some embodiments, the MRI-visible material 146 is a liquid.
According to some embodiments, the MRI-visible material 146 includes
sterile saline or water (e.g., deionized water), with or without vitamin
E and/or Gadolidium.

[0093] According to some embodiments, each pocket 142 has a volume in the
range of about 50 to 500 microliters. According to some embodiments, each
pocket 142 has a nominal height in the range of from about 0.010 to 1
inch. According to some embodiments, each pocket 142 has an area in the
range of from about 4 mm2 to 4 cm2.

[0094] According to some embodiments, the top layer 130 has a nominal
thickness in the range of from about 0.001 to 0.1 inch. According to some
embodiments, the top layer 130 has a total area in the range of from
about 1 to 900 cm2.

[0095] According to some embodiments, the top adhesive 122 is a
biocompatible adhesive that has adhesive properties that ensure a secure,
but releasable bond with base layer 110.

[0096] The MRI-visible tabs 140 can be arranged in a defined pattern 163
(FIG. 3). According to some embodiments and as illustrated, the defined
pattern 163 is a grid pattern, wherein the grid is demarcated by the
voids between the masses 146 of MRI-visible material (generally, the
seams 144). The defined pattern 163 defines a coordinate system 161. The
coordinate system 161 may be codified in any suitable manner. For
example, as illustrated, letter indicia 164 (i.e., "A" to "J") are
provided to designate respective rows of the tabs 140 and number indicia
166 (i.e., "1" to "10") are provided to designate respective columns of
the tabs 140 in the coordinate system 161. However, other markings or
indicators as well as other languages may be used.

[0097] According to some embodiments, the predefined tab array 168
includes a grouping of at least five-by-five tabs 140.

[0098] The reference tab 140R of the tab array 140 is positioned to
indicate an orientation of the top layer 130. According to some
embodiments, the reference tab 140R (or other reference MRI-visible
fiducial element) has a shape that is discernably dissimilar from the
other tabs 140 in an MR image. In this case, the reference tab 140R may
not be positioned to indicate the orientation, but rather the orientation
may be indicated by the orientation of the reference tab 140R.

[0099] Base indicia 150 (FIG. 5) can be provided on the base layer 110 and
define a prescribed pattern and a corresponding coordinate system 151
that in turn corresponds to the coordinate system 161. The base indicia
may be provided on the base layer 110 by etching, printing, molding,
embossing, stamping, pressing or any other suitable technique. According
to some embodiments and as illustrated, the base indicia 150 include grid
lines 152 defining a matrix or grid 153 of sectors 152A. Letter indicia
154 (i.e., "A" to "J") are provided to designate respective rows of the
sectors 152A and number indicia 156 (i.e., "1" to "10") are provided to
designate respective columns of the sectors 152A. Four subsector marks
158 (as shown, cross-hairs or grid lines) are provided in each sector
152A to designate quadrants of the sector 152A.

[0100] Greater on lesser numbers of rows, columns, markers, and subsectors
may be provide.

[0101] The indicia 154, 156 serve as codified indicia representing or
corresponding to the coordinate system 161 of the tab array 168. Each of
the sectors 152A may be sized and positioned to substantially
coextensively align with a respective matched or overlying one of the
tabs 140. The prescribed pattern of the base indicia 150 has higher
resolution than the defined pattern of the array 168 of MRI-visible tabs
140 because the base indicia 150 further include the subsector marks 158
in each sector 152A.

[0102] Operations associated with an exemplary surgical procedure using
the patch assembly 101, according to some embodiments of the present
invention, will now be described with further reference to FIGS. 6-15.
These operations relate to deep brain stimulation procedures. Embodiments
of the present invention are not limited to use with deep brain
stimulation procedures, however, and may be suitable for other surgical
uses including robotic or other type of intrabody surgeries.

[0103] With reference to FIG. 7, the operations may be executed on a head
12 of a patient 10 using a patch assembly 101 as described above and an
interventional system 15. The system 15 includes or is in communication
with an MRI scanner 20, a display 22, an electronic controller 24, a user
interface 26, a trajectory guide apparatus 44 (FIG. 15), and a device
controller 44A (FIG. 15). The controller 24 may include a trajectory
guide module 24B and a patch recognition module 24A (which may be
software or firmware modules, for example).

[0104] The controller 24 may be any suitable computer(s) or the like
adapted to carry out the functions described herein. The user interface
26 may include a man-machine interface to enable an operator to access
and control operations of the system 15. The controller 24 can be
operably connected to each of the display 22 and the MRI scanner 20.

[0105] The surface of the patient's head 12 is suitably prepared by
shaving and cleaning, for example. The release liner 102 is peeled away
from the base layer 110 to expose the base adhesive 120 (FIG. 6). The
patch 100 is applied to the surface of the head 12 such that the flexible
layers 110, 134, 136 conform to the head surface and the patch 100 is
adhered to the head surface by the base adhesive 120 (FIG. 7). An incise
drape or the like may be pre-applied to the skin surface and the patch
100 in turn applied to the incise drape, in which case the patch 110 may
likewise be regarded as being mounted on the surface of the head (albeit
indirectly). The patch 100 is applied at a location such that the grid
pattern 161 spans the region wherein the operator expects to enter the
head 12 with an interventional tool or device.

[0106] With the patch 100 adhered to the patient's head 12, the patient is
placed within an MRI scanner 20. The MRI scanner scans the head 12 and
generates corresponding MR image data. From the MR image data, MR images
are obtained of the patient's head that visualize the patient's skull and
brain. The MR images also visualize the MRI-visible masses 146 of the
patch 100, which serve as MRI-visible landmarks. The MR images can
include volumetric high-resolution images of the brain.

[0107] With reference to FIG. 8, a target region TR (which may also be
referred to as a region of interest or target therapeutic site) in the
head 12 is identified in the MR images. To identify the target region TR,
certain known anatomical landmarks can be used. For example, reference
may be made to physiological landmarks such as the AC, PC and MCP points
(brain atlases give the location of different anatomies in the brain with
respect to these points) and other anatomical landmarks of the patient's
head.

[0108] A target point TP within the target region TR is selected and
designated in a logical space in the MR image. A planned trajectory line
PTL is selected and designated extending from the target point TP to a
desired reference point (such as an operative pivot point of the
trajectory guide apparatus 44 discussed hereinbelow). The planned
trajectory line PTL extends through an entry surface of the head 12 at a
desired entry location point EP in the logical space. According to some
embodiments, the pivot point is located at or proximate the entry
location point EP. Images are obtained in the planned plane of trajectory
to confirm that the trajectory is viable (i.e., that no complications
with anatomically sensitive areas should occur). The steps of identifying
the target region TR, identifying the target point TP, and/or selecting
and designating the planned trajectory line PTL may be executed using or
with the aid of the trajectory guide module 24B, for example.

[0109] A point of intersection IP between the logical planned trajectory
line PTL and the patch 100 in the logical space is determined. More
particularly, according to some embodiments, the point of intersection IP
between the planned trajectory line PTL and the array 168 of MRI-visible
masses 146 is determined.

[0110] The intersection point IP may be determined by visually displaying
the same on the display 22 where it can be readily identified by the
operator (for example, as shown in FIG. 9A). For example, a
representation or highlight of the planned trajectory line PTL and/or the
intersection point IP can be programmatically determined by the
controller 24 and overlaid or projected onto an image 30 of the tab array
168. The image 30 may further include the MR image of the patient and/or
an overlaid representation of the target point TP. The operator can
determine the coordinates of the intersected tab 140 by determining the
row number and column number of the tab 140 in the array 168 (FIG. 1),
for example.

[0111] Alternatively or additionally, the controller 24 may
programmatically identify or recognize and analyze and/or report the
MRI-visible masses 146 in the image data.

[0112] According to some embodiments, the controller 24 (e.g., using the
patch recognition module 24A) processes the acquired image data to
programmatically recognize, orient and place the patch 100 in the logical
space. According to some embodiments, the controller 24 uses an algorithm
to programmatically determine the position of the tab array 168 in the
logical space. According to some embodiments, the controller uses a
pre-stored reference image or images to programmatically determine the
position of the tab array 168 in the logical space.

[0113] Once the controller 24 has assessed the position (e.g., including
orientation) of the patch 100 in the logical space, the controller 24 can
use this data to identify the intersection point IP or enable or assist
identification of the intersection point IP by the operator. For example,
the controller 24 may enhance (e.g., add increased image contrast) or
insert highlighted representations of the tabs 140 into the image 30 as
provided on the display 22 in order to make the intersected tab 140
and/or the tab array 168 visually stand out in the image 30.

[0114] According to some embodiments, the controller 24 generates, fits
and overlays or superimposes a graphical grid overlay 31 onto the MR
image 30 as shown in FIG. 9B, for example, to delineate the location and
distribution of the patch 100 on the head. The positions and orientations
of the patch 100 and the MRI-visible tab may be correlated to the image
of the head 12 by the graphical grid overlay 31. According to some
embodiments, the graphical grid overlay 31 is fitted to the contours of
the patch 100 in three dimensional space as illustrated, for example.
This may be accomplished by segmenting the image of the tab array 168 and
incorporating assessed angle data (of the edges of the tabs 140) in the
process of drawing and fitting the graphical grid overlay 31.

[0115] The controller 24 may determine and report or indicate the
coordinates from the grid 163 corresponding to the intersection point IP
to the operator (e.g., visually via the display 22 and/or audibly via a
sound transducer). For example, in FIG. 9A, the intersection point IP is
located in the MRI-visible tab 140 located in column 5 and row C of the
grid 163, and the graphical representation of the intersection point IP
is labeled in the image 30 with these coordinates (as illustrated, "(7,
D)", designating the tab 140 at column "7" and row "D") and a graphic
overlay 32. The operator and/or the controller 24 can also determine the
portion or region (e.g., quadrant) of the tab 140 within which the
intersection point IP resides.

[0116] The reference tab 140R can be identified in the image 30 and used
by the operator and/or the controller 24 to determine and register the
orientation of the coordinate system 161 of the patch 100 in the logical
(i.e., MR volume) frame of reference.

[0117] The controller 24 can provide various additional functionality once
it has recognized the tab array 168 in the MR image 30. According to some
embodiments, the controller 24 will issue an alert (e.g., visible or
audible) to the operator if the planned trajectory line PTL does not
intersect the grid 163. According to some embodiments, the controller 24
will initially position a provisional planned trajectory line through the
center of the grid 163. The operator can then move the provisional
planned trajectory line in the display as needed to arrive at the desired
ultimate planned trajectory line PTL.

[0118] The physical location on the top layer 130 corresponding to the
intersection point IP can be readily determined using the image from the
MR image data (e.g., by comparison to the image of the tabs 140 in the MR
image and/or by reference to the coordinate system 161). Because the top
layer 130 is affixed to the head 12 and the relationship between the
patient's scalp and the MRI-visible tabs 140 is thereby maintained, the
physical location of the intersection point IP (and, thus, the entry
location point EP) can likewise be readily identified.

[0119] According to some embodiments and as illustrated, the thickness of
the patch 100 between the tabs 140 and the underlying surface of the head
12 is thin (e.g., no more than 0.003 and 0.100 inch) so that the
intersection point IP between the planned trajectory line PTL and the
array 168 is substantially the same or closely proximate the intersection
point between the planned trajectory line PTL and the surface of the head
12.

[0120] Once the MR image(s) have been acquired for determining the
intersection point IP, the patient can be withdrawn from the scanning
apparatus 20 to facilitate access to the patient's head 12. The operator
removes the top layer 130 from the base layer 110 to reveal the base
layer 110 by lifting an edge of the top layer 130 and peeling the top
layer 130 away from the base layer 110 as shown in FIG. 10, for example.

[0121] With the base layer 110 remaining on the head 12 and exposed, the
operator identifies the location (referred to herein as the label point
LP) on the base layer 110 corresponding to the location of the
intersection point IP in the top layer 130. This identification may be
enabled by a prescribed correspondence between the coordinate system 151
of the base layer 110 and the array 168 of MRI-visible tabs 140 (FIG. 5).
For example, in the foregoing step, the operator may determine that the
intersection point IP was located in the top, right quadrant of the tab
140 located at column "5", row "C" of the array 168. The operator can, in
the present step, locate the quadrant located in the top, right quadrant
of the square sector 152A (FIG. 5) located at column "5", row "C" of the
coordinate system 151 and identify this quadrant as the corresponding
label point LP. According to some embodiments, the coordinate system 151
(FIG. 5) is readily legible on the base layer 110 so that the operator
can expeditiously and reliably identify the label point LP without
special tools or cumbersome procedure.

[0122] Having identified the label point LP, the operator may thereafter
mark the head 12 at a location on the head surface corresponding to the
label point LP. According to some embodiments, the operator marks the
head surface at a location immediately below the label point LP. It will
be appreciated that this location on the head surface is substantially
the same as the intended entry location point EP designated above for the
planned trajectory line PTL. The patch 100 thus can provide precise
correlation between the logical points in the scanned MR volume and the
physical patient.

[0123] The operator can mark the head 12 at or proximate the desired entry
location using a suitable tool or implement. According to some
embodiments and as shown in FIG. 11, the operator uses a marking tool 40
in the form of a driver. The operator presses the marking tool 40 into
the patient's head 12 such that the marking tool 40 penetrates through
the skin and may partially penetrate into the skull. The marking tool 40
may be driven through the base layer 110 and into the head 12.
Alternatively, the operator may lift or remove a portion of the base
layer 110 to expose the location on the scalp to be marked and then mark
the scalp. A visually identifiable mark 14 (FIG. 13) will thereafter
remain in the patient's scalp and/or skull for the physician's reference.
Suitable marking tools may include marking tools as disclosed in
co-assigned U.S. Provisional Patent Application No. 61/041,500 [Attorney
Docket No. 9450-36PR], the disclosure of which is incorporated herein by
reference. Alternatively, the operator may mark the scalp with ink or
other suitable material.

[0124] The base layer 110 is removed (e.g., peeled away) from the head 12
as shown in FIG. 12.

[0125] A burr hole 16 (FIG. 14) can thereafter be formed in the head 12 at
the location of the mark 14 using any suitable technique or device (e.g.,
drilling). A burr hole ring 42 (FIG. 14) may be affixed to the skull 12
overlying the burr hole 16.

[0126] The procedure may thereafter be continued using the burr hole 16 as
an access portal to the brain and employing suitable instrumentation such
as the trajectory guide apparatus 44. The trajectory guide apparatus 44
can be fixed to the skull of the patient as shown in FIG. 15, for
example. The trajectory guide apparatus 44 may allow the operator to
align an access path trajectory to the internal target site TP, such that
the interventional/surgical device/lead, therapy, etc. will be delivered
to the target site following the desired trajectory (e.g., the planned
trajectory line PTL) through the cranial tissue. This trajectory goes
through the entry location point EP. The interventional device (e.g.,
probe, lead or the like) can be advanced through a targeting cannula 44B
of the trajectory guide apparatus 44, into the head 12 and to or
proximate the target point TP. In some embodiments, the trajectory guide
apparatus 44 can pivot the targeting cannula 44B about a pivot point at
or proximate the entry point location EP. The trajectory guide apparatus
44 may be remotely repositioned using a trajectory guide apparatus
controller 44A, for example. Suitable trajectory guide apparatus and
methods may include those disclosed in co-assigned PCT Application No.
PCT/US2006/045752 [Attorney Docket No. 9450-8WO] and co-assigned U.S.
patent application Ser. No. 12/134,412 [Attorney Docket No. 9450-34], the
disclosures of which are incorporated herein by reference.

[0127] In some embodiments, the controller 24 is in communication with a
graphical user interface (GUI) that allows a clinician to define a
desired trajectory and/or end position on a displayed image, then can
electronically convert the orientation/site input data programmatically
to generate position data for the trajectory guide apparatus 44. The GUI
can include an interactive tool that allows a clinician to draw, trace or
otherwise select and/or identify the target treatment site and/or access
path trajectory. The system 15 can then be configured to identify
adjustments to the trajectory guide apparatus 44 that are most likely to
achieve this trajectory.

[0128] In some embodiments, the user interface 26 can be configured to
electronically determine the location of a targeting cannula and a
trajectory associated therewith. The user interface 26 can be configured
to display MRI images with the planned trajectory and intersection
point(s) that will be followed if the interventional/surgical device/lead
is advanced using a defined position of the trajectory guide apparatus
44.

[0129] According to some embodiments the patch assembly 101 is packaged as
a medical kit with the marking tool 40. The patch assembly 101 may be
used in conjunction with a burr hole forming tool (e.g., a drill)
configured to drill, cut or otherwise form a burr hole through the
patient's skull 12. According to some embodiments, the marking tool 40
and the burr hole forming tool are formed of MRI-compatible materials.

[0130] With reference to FIG. 16, a patch assembly 201 according to
further embodiments of the present invention is shown therein. The patch
assembly 201 corresponds to the patch assembly 101 except that the tabs
240C of the center row and the center column of the tab array 268 have a
geometric shape (as shown, circular) different than the geometric shape
(as shown, rectangular) of the remaining tabs 240. The respective shapes
are distinguishable from one another when observed in the MR image. This
combination of dissimilar tab shapes may assist the operator or
controller 24 in identifying the location of the tab 240 or 240C
intersecting the planned trajectory line PTL.

[0131] With reference to FIGS. 17-19, patches 300, 400, 500 according to
further embodiments of the present invention are shown therein. The
patches 300, 400, 500 each correspond to the patch 100 except that they
further include perforations extending through the top layers 330, 430,
530 thereof between the tabs 340, 440, or 540. As illustrated, in some
embodiments, the perforations may be configured as closed slits 339,
circular holes 439, or open, elongated slots 539. In use, the
perforations may help the top layer 330, 430, 530 to conform to the
patient's head. The base layers 310, 410, 510 may also include
perforations (e.g., extending along the grid lines) to help the base
layer 310, 410, 510 conform to the patient's head. According to some
embodiments, reliefs that do not extend fully through the top layer 330,
430, 530 may be used in place of the perforations.

[0132] With reference to FIG. 20, a base layer 610 according to further
embodiments of the present invention is shown therein. The base layer 610
may be used in place of the base layer 110 for the patch 100, for
example, and corresponds to the base layer 110 except as follows. The
base layer 610 can include a grid of perforations 614 generally
coextensive with the grid of the base coordinate system 651. The base
layer 610 may be used in the same manner as the base layer 110 except
that the operator may selectively tear away or remove a section of the
base layer 610 along the perforations 614 in order to expose the
underlying scalp for marking with the marking tool. According to further
embodiments, the base layer 110 may be rendered frangible by score lines
or other suitable features.

[0133] With reference to FIGS. 21 and 22, a patch 700 according to further
embodiments of the present invention is shown therein. The patch 700
corresponds to the patch 100 except that the tabs 740 thereof can be
removed individually or in subgroups from the remainder or the top layer
730. In use, the operator can remove a selected one or ones of the tabs
740 from the patient's head to reveal the underlying base layer 710. The
base layer 710 may also be frangible (e.g., including perforations
corresponding to the perforations 614), in which case the underlying
segment of the base layer 710 may also be selectively removed to expose
the patient's scalp for marking. Indicia 755 may be visible on the base
layer 710 where the tabs 740 have been removed.

[0134] With reference to FIG. 23, a patch 800 according to further
embodiments of the present invention is shown therein. The patch 800 may
correspond to the patch 100 except that the tab array 868 of the patch
800 includes rows of MRI-visible tabs 840G, 840H, 8401 having distinctly
different geometric shapes (as shown, a circular shape, a square shape,
and a triangular shape, respectively). The different tab shapes are
discernable from an MR image of the patch 800 by an operator and/or the
controller 24. The configuration of the tab array 868 may facilitate
determination of the orientation of the patch 100 in logical space and/or
identification of the tab 840G, 840H, 8401 intersected by the planned
trajectory line PTL.

[0135] With reference to FIG. 24, a patch 900 according to further
embodiments of the present invention is shown therein. The patch 900 may
correspond to the patch 100 except that the patch 900 includes a mesh
("fishnet") substrate 930 to which an array 968 of MRI-visible tabs 940
(corresponding to the tabs 140) are secured. The substrate 930 can be
elastic or stretchable to readily deform or conform to the contours of a
head 12. The patch 900 may be used in the same manner as the patch 100
except that in some embodiments the patch 900 may not include any base
layer corresponding to the base layer 110. In this case, the operator may
identify and mark the desired location (e.g., the point of intersection
IP) through the openings 930A of the mesh substrate 930 and the mesh
substrate 930 may be adhered directly to the head (or an incise drape) by
adhesive on the back surface of the mesh substrate 930. The controller 24
may recognize and assess the tab array 968 and construct a modified grid
in logical space that corresponds to the distorted or irregular
distribution of the tabs 940 caused by the stretching of substrate 930.
The controller 24 may recognize and assess the tab array 968 and
construct a modified grid in logical space that corresponds to the
distorted or irregular distribution of the tabs 940 caused by the
stretching of the substrate 930. According to still further embodiments,
the layers 110 and 130 of the patch 100 may be stretchable (with or
without being meshes) to enable similar stretchable conformability to the
head 12.

[0136] With reference to FIG. 25, a top layer 1030 according to further
embodiments of the present invention is shown therein. The top layer 1030
may be used in place of the top layer 130, for example. The top layer
1030 differs from the top layer 130 in that the top layer 1030 includes
MRI-visible tabs 1040 each having a height dimension H1 greater than its
width W1. The height of each tab 1040 is sufficient to permit the
controller 24 and/or an operator to determine the orientation of a
heightwise axis AH-AH of the tab 1040. This additional information can be
employed to more accurately assess the point of intersection IP with the
planned trajectory line PTL.

[0137] With reference to FIG. 26, a base layer 1110 according to further
embodiments of the present invention is shown therein. The base layer
1110 may be used in place of the base layer 110 or the base layer 610,
for example. The base layer 1110 differs from the base layer 610 in that
the base layer 1110 includes a supply of ink 1180 therein and/or thereon.
When the base layer 1110 is applied to the head 12, the ink 1180
transfers to the head 12 to leave an ink pattern 1182 on the surface of
the head. For example, the ink pattern 1182 can include a full or partial
duplicate 1182A of the grid lines 1152 on the base layer 1110 and/or
textual or codified indicia 1182B indicating the coordinates. The base
layer 1110 can be used in the same manner as the base layer 110 or the
base layer 610 except that the base layer 1110 can be fully or partially
removed prior to marking the head 12 with a marking tool or the like. In
this case, the ink pattern 1182 remains on the scalp to assist the
operator in marking the physical location corresponding to the
intersection point IP determined from the MR image 30.

[0138] The ink 1180 may be any suitable material that can transfer from
the base layer 1110 to the patient's scalp, bond or adhere to the scalp,
and provide a suitably visible contrast with the scalp. The ink may be a
liquid or powder, for example.

[0139] According to further embodiments, the ink supply may be provided in
or on the substrate including the MRI-visible tabs (e.g., the top layer
130) in which case the base layer (e.g., the base layer 110) can be
omitted. The substrate can be removed after the MRI scan is taken,
leaving the ink pattern on the scalp of the head 12 to provide the
reference grid on the head 12 for locating the physical location of the
intersection point IP.

[0140] With reference to FIG. 27, a patch system 1203 and method according
to further embodiments of the present invention are illustrated therein.
The patch system 1203 includes a plurality of the patches 100, for
example, applied to the patient 12 in close proximity to one another to
form a patch array 1208. The patches 100 may be tiled together (i.e.,
placed in close proximity to one another) and may or may not be
immediately adjacent one another or overlapping. The patch system 1203
may be used in generally the same manner as the patch 100 as described
above, except that the patch system 1203 will cover a greater surface
area on the patient and only one of the patches 100 thereof will be
intersected by the planned trajectory line PTL. The operator may visually
determine which of the patches contains the intersection point IP and
where the intersection point IP lies in the patch. According to some
embodiments, the controller 24 programmatically assesses the patch system
1203 in the MR image to determine and indicate, report or otherwise
process the positions of the patches 100 as discussed above with regard
to the patch 100. The controller 24 may correlate the plurality of
patches 100 with respect to one another so that the patch system 1203 can
be assessed and processed in substantially the same manner as the single
patch 100. The controller 24 may programmatically account for variations
resulting from relative placements of the patches 100 in the patch array
1208. According to some embodiments, the controller 24 determines the
orientation of each patch 100 using each patch's respective reference tab
140R as described above.

[0141] Still further embodiments of the present invention may incorporate
aspects or features as described herein in other forms, combinations
and/or applications. For example, a flexible substrate having selectively
removable MRI-visible tabs (such as the substrate 730 and the tabs 740)
may be provided without a base layer (e.g., the base layer 710) and may
be directly applied to a patient's body surface or incise drape.

[0142] By way of further example, a patch may be provided having a base
layer (e.g., corresponding to the base layer 110) and a removable top
layer (e.g., corresponding to the top layer 130), but wherein the top
layer carries only a single (i.e., exactly one) MRI-visible fiducial
element or tab. The single MRI-visible fiducial element may have an
asymmetric shape that is discernable in an MRI image so that the
orientation of the patch in the logical space can be determined from the
MRI image data. According to some method embodiments, the orientation of
a patch (with or without a base layer) having only a single MRI-visible
fiducial element is programmatically determined (e.g., by the controller
24) from the MRI image data. According to still further embodiments, the
patch (with our without a base layer) may have a plurality of MRI-visible
fiducial elements, but wherein the fiducial elements are not arranged in
a defined pattern.

[0143] Two patches (or groups of patches) in accordance with the present
invention (e.g., two of the patches 100) can be employed together to
identify and mark two entry location points for a bilateral surgical
procedure on a patient's head. The two patches 100 may be concurrently
mounted on the head and each patch used in the same manner as discussed
above. In this case, the controller 24 may programmatically distinguish
between the two patches and their respective planned trajectory lines PTL
so that the point of intersection IP for each patch can be determined
independently of the other. The controller 24 may simultaneously display
the patches 100 and their associated points of intersection IP, planned
trajectory lines PTL, graphical overlays and the like.

[0144] The system 15 (FIG. 7) can include circuits or modules that can
comprise computer program code used to automatically or
semi-automatically carry out operations to generate multi-dimensional
visualizations during an MRI guided therapy. FIG. 28 is a schematic
illustration of a circuit or data processing system 80 that can be used
with the system 15. The circuits and/or data processing systems 80 data
processing systems may be incorporated in a digital signal processor in
any suitable device or devices. As shown in FIG. 28, the processor 82
communicates with an MRI scanner 20 and with memory 84 via an
address/data bus 85. The processor 82 can be any commercially available
or custom microprocessor. The memory 84 is representative of the overall
hierarchy of memory devices containing the software and data used to
implement the functionality of the data processing system. The memory 84
can include, but is not limited to, the following types of devices:
cache, ROM, PROM, EPROM, EEPROM, flash memory, SRAM, and DRAM.

[0145] As shown in FIG. 28 illustrates that the memory 84 may include
several categories of software and data used in the data processing
system: the operating system 86; the application programs 88; the
input/output (I/O) device drivers 92; and data 90. The data 90 can also
include tool and patient-specific image data 90A. FIG. 28 also
illustrates the application programs 88 can include the patch recognition
module 24A and the trajectory guide module 24B.

[0146] As will be appreciated by those of skill in the art, the operating
systems 452 may be any operating system suitable for use with a data
processing system, such as OS/2, AIX, DOS, OS/390 or System390 from
International Business Machines Corporation, Armonk, N.Y., Windows CE,
Windows NT, Windows95, Windows98, Windows2000 or other Windows versions
from Microsoft Corporation, Redmond, Wash., Unix or Linux or FreeBSD,
Palm OS from Palm, Inc., Mac OS from Apple Computer, LabView, or
proprietary operating systems. The I/O device drivers 92 typically
include software routines accessed through the operating system 86 by the
application programs 88 to communicate with devices such as I/O data
port(s), data storage 90 and certain memory 84 components. The
application programs 88 are illustrative of the programs that implement
the various features of the data processing system and can include at
least one application, which supports operations according to embodiments
of the present invention. Finally, the data 90 represents the static and
dynamic data used by the application programs 88, the operating system
86, the I/O device drivers 92, and other software programs that may
reside in the memory 84.

[0147] While the present invention is illustrated, for example, with
reference to the modules 24A-24B being application programs in FIG. 28,
as will be appreciated by those of skill in the art, other configurations
may also be utilized while still benefiting from the teachings of the
present invention. For example, the modules 24A, 24B and/or may also be
incorporated into the operating system 86, the I/O device drivers 92 or
other such logical division of the data processing system. Thus, the
present invention should not be construed as limited to the configuration
of FIG. 28 which is intended to encompass any configuration capable of
carrying out the operations described herein. Further, one or more of
modules, i.e., modules 24A, 24B can communicate with or be incorporated
totally or partially in other components, such as an MRI scanner.

[0148] The I/O data port can be used to transfer information between the
data processing system, the MRI scanner, the tool and another computer
system or a network (e.g., the Internet) or to other devices controlled
by the processor. These components may be conventional components such as
those used in many conventional data processing systems, which may be
configured in accordance with the present invention to operate as
described herein.

[0149] The foregoing is illustrative of the present invention and is not
to be construed as limiting thereof. Although a few exemplary embodiments
of this invention have been described, those skilled in the art will
readily appreciate that many modifications are possible in the exemplary
embodiments without materially departing from the teachings and
advantages of this invention. Accordingly, all such modifications are
intended to be included within the scope of this invention as defined in
the claims. The invention is defined by the following claims, with
equivalents of the claims to be included therein.